zap technology. departure. hertz gold plus rewards also offers ereturn-- our fastest way to return your car. just note your mileage and zap ! you're outta there ! we'll e-mail your receipt in a flash, too. it's just another way you'll be traveling at the speed of hertz. >>> if you're just joining us, if you haven't heard yet the senate failed to advance the portion of the gun control measure that would require background checks. they needed the 60 votes. they got 54 votes on that. president obama will be hosting a news conference at 5:30 eastern time on the gun control measure. and "fast money" will take us live to that. stay tuned for that. michelle? >> bill, the latest from boston is the authorities have solid leads but as of now, no arrest. joining us is clint van zandt. he's a former hostage negotiator. he worked on many cases from the oklahoma city bombings to the unabomber. >> welcome back. >> good to be with you. >> based on everything we know about the bomb that was used, what kind of person did this? >